The Effect of a Concentration of Water on the Mass of a Potato

The Effect of a Concentration of Water on the Mass of a Potato

Aim:

My aim is to find the percentage change of mass when a small piece of

potato is placed in to molar sucrose solution

Apparatus:

* Molar sucrose solution 0.0 - 0.5

* Potato

* Cutting board

* Knife

* Weighing machine

* Glass test tube

* Glass test tube holder

Plan: -

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My plan is too find the percentage change of mass of a small piece of

potato when placed in to molar sucrose solution by using osmosis.

Osmosis is explained below

Osmosis

Osmosis is the passage of water molecules from a region of their high

concentration to a region of their low concentration through a

partially permeable membrane. It is best regarded as a form of

diffusion in which only water molecules move. For example look at

Figure 2. The solute molecules are too large to pass through the pores

in the membrane, so the movement of water molecules can only achieve

equilibrium. Solution A has the higher concentration of water; so

there will be a net movement of water from A to B by osmosis. At

equilibrium there will be no further net movement of water. The

tendency of water molecules to move from one place to another is

measured as the water potential, represented by the symbol Y (greek

letter psi). water always moves from a region of higher pottential to

one lower water pottential. solute molecules reduce Y (in effect, they

dilute the water). The extent by which they lower Y is known as the

solute potential, given the symbol Ys.

Terms used

In 1988 the institute of biology recommended the use of the term water

potential to describe water movement through membranes. The two main

factors affecting the water potential of plant cells are solute

concentration and the pressure generated enters and inflates plant